RSPB study decline of waders (1 Viewer)

A recent RSPB study into the decline of waders over the last 25 years has found a variety of contributing factors to do with land use. Waders like lapwings and curlew do better in grouse moors and in areas where their are low local populations of crows. I cannot locate the original report, which will be published in the International Scientific Journal of Bird Study

It seems that the study squarly points a finger toward predation as a powerful cause of wader species decline, giving strong support for the land game management argument.

There is still no official press release from the RSPB, even though it was apparantly ready for release on the 17th of feb. The only copy of the press release I could find was on this blog,

http:
//jamesmarchington.blogspot.com/

There are various versions of the study summary in most birdy websites, eg,
http://www.birdwatch.co.uk/channel/newsitem.asp?c=11&cate=__10413

Surley, as we have discussed on other threads, the real issue is loss of habitat due to agriculture, which acts to exaggerate the effect predation has on species numbers. The RSPB press release doesnt do a very good job of pointing this out.

If anyone can locate, or get hold of the results of this study, I'd very much like to see it/them. It seems poor timing for the RSPB who recently spoke out against the proposed corvid cull, right before it receives a report which seems to be in support of it (at least for waders).

Shadow-watcher said:

A recent RSPB study into the decline of waders over the last 25 years has found a variety of contributing factors to do with land use. Waders like lapwings and curlew do better in grouse moors and in areas where their are low local populations of crows. I cannot locate the original report, which will be published in the International Scientific Journal of Bird Study

It seems that the study squarly points a finger toward predation as a powerful cause of wader species decline, giving strong support for the land game management argument.

There is still no official press release from the RSPB, even though it was apparantly ready for release on the 17th of feb. The only copy of the press release I could find was on this blog,

http:
//jamesmarchington.blogspot.com/

There are various versions of the study summary in most birdy websites, eg,
http://www.birdwatch.co.uk/channel/newsitem.asp?c=11&cate=__10413

Surley, as we have discussed on other threads, the real issue is loss of habitat due to agriculture, which acts to exaggerate the effect predation has on species numbers. The RSPB press release doesnt do a very good job of pointing this out.

If anyone can locate, or get hold of the results of this study, I'd very much like to see it/them. It seems poor timing for the RSPB who recently spoke out against the proposed corvid cull, right before it receives a report which seems to be in support of it (at least for waders).

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Shadow-watcher,
Have you got the title "International Scientific Journal of Bird Study" right? It doesn't come up under that title when I googled it. Can you check your source?
MJB

MJB said:

Shadow-watcher,
Have you got the title "International Scientific Journal of Bird Study" right? It doesn't come up under that title when I googled it. Can you check your source?
MJB

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Thats weird, but mjh73 has found it. Much obliged:t:

mjh73 said:

http://www.informaworld.com/smpp/content~db=all~content=a933574892~frm=titlelink

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Thanks mjh73. As I thought it might be, it's Bird Study. My copy hasn't arrived yet!
MJB

Shadow-watcher said:

Surley, as we have discussed on other threads, the real issue is loss of habitat due to agriculture, which acts to exaggerate the effect predation has on species numbers. The RSPB press release doesnt do a very good job of pointing this out.

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The problem is wether we like it or not habitat loss is a problem here to stay and most probably get worse not better,predation however is potentially a much easier problem to deal with, it might not be the perfect solution in an ideal world but its better than doing nothing and since when did we live in an ideal world.

Shadow-watcher said:

There is still no official press release from the RSPB, even though it was apparantly ready for release on the 17th of feb. The only copy of the press release I could find was on this blog,

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The press release has been used in many publications including the one mentioned above. They must have all used the official press release

There is something at http://www.rspb.org.uk/ourwork/proj...impact-of-predation-on-ground-nesting-waders-

Some work appears to have been undertaken to reduce mammalian predation by habitat change without a lot of success. Interestingly it seems to single out mammalian predators as most predation was carried out at night.

I am not sure if this is the same project.

Thanks to all of you for helping clear this up and point me in the right direction

like everything else, birds disappeared at around or after the advent of organo-phosphate chemicals. whilest predation has its impact, we always have had preditors. only in the past 25 years does there seem to have been any problem.

cates said:

like everything else, birds disappeared at around or after the advent of organo-phosphate chemicals. whilest predation has its impact, we always have had preditors. only in the past 25 years does there seem to have been any problem.

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I agree that negative human impact has put pressures so excessive on wild populations that predation has become a valid threat to their existance. But as others in this thread have well pointed out, if predator control is the only viable option we have to protect species then we must unfortunatly practice it. Its the misuse of that philosophy that is the problem.

It seems to have taken a long time for the RSPB to wake up to the fact that there’s a serious decline in our wader populations, we’ve been saying it for nearly 30 years. Rapid decline started in the north of Scotland when there was whole scale forestation of the flows and bogs coupled with the grants for land drainage which ate up most of the upland pasture breeding and wet meadow feeding areas. Crop rotations that left very little food for the birds to Winter on put the finishing touches to the decline, I can’t see it being any different in other wader breeding, feeding and Wintering areas. As for the Crow predation being a factor, well, there are now fewer Hoodie Crows in the north of Scotland than there ever was, the intensive use of Larson traps have made sure of that. This has also had the knock on effect of reducing the number of nesting sites for species such as Merlin, Kestrel, Long-eared and Tawny Owls. Raptors such as Hen Harrier are at their lowest levels ever, Sparrowhawk and Kestrels are declining, Peregrines are declining in moorland areas but increasing in populated urban areas. Short-eared Owls are now a scarce breeder but Buzzards and Red Kites are doing well, at least in some areas where they are not poisoned they are. I'm sure that the problem that has reduced our waders to such low levels has little or nothing to do with our Raptors, the biggest problem they face is from us humans destroying their habitat and feeding areas and pretending it's the fault of something else.

nirofo.

nirofo said:

Rapid decline started in the north of Scotland when there was whole scale forestation of the flows and bogs coupled with the grants for land drainage which ate up most of the upland pasture breeding and wet meadow feeding areas. Crop rotations that left very little food for the birds to Winter on put the finishing touches to the decline, I can’t see it being any different in other wader breeding, feeding and Wintering areas. As for the Crow predation being a factor, well, there are now fewer Hoodie Crows in the north of Scotland than there ever was, the intensive use of Larson traps have made sure of that. This has also had the knock on effect of reducing the number of nesting sites for species such as Merlin, Kestrel, Long-eared and Tawny Owls. Raptors such as Hen Harrier are at their lowest levels ever, Sparrowhawk and Kestrels are declining, Peregrines are declining in moorland areas but increasing in populated urban areas. Short-eared Owls are now a scarce breeder but Buzzards and Red Kites are doing well, at least in some areas where they are not poisoned they are. I'm sure that the problem that has reduced our waders to such low levels has little or nothing to do with our Raptors, the biggest problem they face is from us humans destroying their habitat and feeding areas and pretending it's the fault of something else.
nirofo.

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Is it not two issues though?
They set out to answer the question "what are the current threats to upland bird populations" and an important part of the answer was avian predation.

What is driving the predation is another matter. I guess one theory might be that, because of the habitat destruction prey availability has reduced and those habitats that are around are more 'patchy' which I guess would force predators to more intensively predate those patches they do find? This would tie the predation in to habitat change. Less predators BUT chasing less prey in a much smaller area.

The next question being "what do we do to stabilise and reverse the decline in upland birds". And a short term answer might include some localised predator control. Even though the long term answer would be to increase the habitat availability so that there are more sites for the upland birds under threat and, hopefully the predators become more dispersed and exert less pressure without the need for conservation intervention.

Please note I am just theorising, I have not studied the specific case at all!

mjh73 said:

Is it not two issues though?
They set out to answer the question "what are the current threats to upland bird populations" and an important part of the answer was avian predation.

What is driving the predation is another matter. I guess one theory might be that, because of the habitat destruction prey availability has reduced and those habitats that are around are more 'patchy' which I guess would force predators to more intensively predate those patches they do find? This would tie the predation in to habitat change. Less predators BUT chasing less prey in a much smaller area.

The next question being "what do we do to stabilise and reverse the decline in upland birds". And a short term answer might include some localised predator control. Even though the long term answer would be to increase the habitat availability so that there are more sites for the upland birds under threat and, hopefully the predators become more dispersed and exert less pressure without the need for conservation intervention.

Please note I am just theorising, I have not studied the specific case at all!

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I don't doubt that in areas where wader and other upland/moorland birds are reduced in numbers and the Raptor numbers remain the same, (for a while), then predation will reduce them even further. Fortunately in real life nature doesn't work like that, at least not for long anyway. If the Raptors reduce the prey species they depend on to levels below which they can sustain themselves, then the Raptors will either starve to death if they stay put, or they will have to find new hunting territories with enough prey to keep them alive. If they are to breed successfully then even higher densities of prey are a necessity. The belief that in areas where Raptors are breeding successfully they must be decimating the prey to such an extent that there are hardly any left, is a fallacy perpetrated by organisations like Songbird Survival and the Countryside Alliance to further their own ends, if they are breeding successfully, then so are the other birds in the territory. If anyone who has taken their blinkers off cares to study this phenomenom they will see that Raptors are not prone to committing suicide by eating up every last bird that flies their way, they have enough to contend with from the gamekeepers. As I said before, the biggest threat to the suvival of all our birds, and that includes waders, songbirds and raptors is us. !!!

nirofo.

mjh73 said:

Is it not two issues though?
They set out to answer the question "what are the current threats to upland bird populations" and an important part of the answer was avian predation.

What is driving the predation is another matter. I guess one theory might be that, because of the habitat destruction prey availability has reduced and those habitats that are around are more 'patchy' which I guess would force predators to more intensively predate those patches they do find? This would tie the predation in to habitat change. Less predators BUT chasing less prey in a much smaller area.

The next question being "what do we do to stabilise and reverse the decline in upland birds". And a short term answer might include some localised predator control. Even though the long term answer would be to increase the habitat availability so that there are more sites for the upland birds under threat and, hopefully the predators become more dispersed and exert less pressure without the need for conservation intervention.

Please note I am just theorising, I have not studied the specific case at all!

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Widespread afforestation plus increased sheep numbers destroyed habitat and boosted populations of Corvids and foxes. That is the begining and end of it. The idea that Raptors are somehow a major factor is simply BS spun for the benefit of shooting estates that give free reign to criminal gamekeepers.

EG: A recent study on Hen Harriers diet in this country where Red Grouse are in big trouble thanx to habitat destruction found that of 1000 samples tested, only 1 had any Grouse remains in it!!!

Irish Kite said:

Widespread afforestation plus increased sheep numbers destroyed habitat and boosted populations of Corvids and foxes. That is the begining and end of it. The idea that Raptors are somehow a major factor is simply BS spun for the benefit of shooting estates that give free reign to criminal gamekeepers.

EG: A recent study on Hen Harriers diet in this country where Red Grouse are in big trouble thanx to habitat destruction found that of 1000 samples tested, only 1 had any Grouse remains in it!!!

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Maybe I missed it, but where exactly did I talk about raptors in my post that you have quoted?

I very carefully used 'predators' because I was not talking about raptors but the range of predators - including foxes and corvids. The RSPB paper, which I have not read fully yet, talks about the impact of afforestation as well as the impact of corvid predation.

nirofo said:

I don't doubt that in areas where wader and other upland/moorland birds are reduced in numbers and the Raptor numbers remain the same, (for a while), then predation will reduce them even further. Fortunately in real life nature doesn't work like that, at least not for long anyway. If the Raptors reduce the prey species they depend on to levels below which they can sustain themselves, then the Raptors will either starve to death if they stay put, or they will have to find new hunting territories with enough prey to keep them alive. If they are to breed successfully then even higher densities of prey are a necessity. The belief that in areas where Raptors are breeding successfully they must be decimating the prey to such an extent that there are hardly any left, is a fallacy perpetrated by organisations like Songbird Survival and the Countryside Alliance to further their own ends, if they are breeding successfully, then so are the other birds in the territory. If anyone who has taken their blinkers off cares to study this phenomenom they will see that Raptors are not prone to committing suicide by eating up every last bird that flies their way, they have enough to contend with from the gamekeepers. As I said before, the biggest threat to the suvival of all our birds, and that includes waders, songbirds and raptors is us. !!!

nirofo.

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You also appear to have quoted my message completely out of context.
You seem to have jumped to this being a raptor issue. The RSPB paper does not mention raptors AT ALL that I can see, and nor did I. The paper is focussed on the issue of corvid predation, and to a degree how (anthropogenic) habitat change has changed crow abundance.

Prey switching makes it quite possible for a predator to wipe out populations of prey without forcing themselves into starvation. Also this statement

If they are to breed successfully then even higher densities of prey are a necessity.

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does not make sense. Birds have many mechanisms for ensuring they can provision themselves and their young as successfully as possible. Larger territory, prey switching, reduced clutch sizes etc. They have no control over the density of prey so they are more likely to adapt themselves first. Again we are talking about corvids here and they have generally proven themselves to be highly adaptable historically.

As an example, raven's have been found to be hammering the populations of some breeding shorebirds in SE Australia. The birds have territories on and around housing estates (where they can scavenge most of the time) but have learnt to patrol nearby remnants of dune system and saltmarsh during the shorebird breeding season for the eggs and chick. It is quite possible that they will drive some local wader populations extinct without any impact whatsoever on their own populations.

mjh73 said:

You also appear to have quoted my message completely out of context.
You seem to have jumped to this being a raptor issue. The RSPB paper does not mention raptors AT ALL that I can see, and nor did I. The paper is focussed on the issue of corvid predation, and to a degree how (anthropogenic) habitat change has changed crow abundance.

Prey switching makes it quite possible for a predator to wipe out populations of prey without forcing themselves into starvation. Also this statement does not make sense. Birds have many mechanisms for ensuring they can provision themselves and their young as successfully as possible. Larger territory, prey switching, reduced clutch sizes etc. They have no control over the density of prey so they are more likely to adapt themselves first. Again we are talking about corvids here and they have generally proven themselves to be highly adaptable historically.

As an example, raven's have been found to be hammering the populations of some breeding shorebirds in SE Australia. The birds have territories on and around housing estates (where they can scavenge most of the time) but have learnt to patrol nearby remnants of dune system and saltmarsh during the shorebird breeding season for the eggs and chick. It is quite possible that they will drive some local wader populations extinct without any impact whatsoever on their own populations.

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You did mention avian predators which I assumed included Raptors, certainly in my neck of the woods it does, the corvids having been drastically reduced in numbers as I stated in my original post. The far north of Scotland is predominantly hill, flow bog and moorland with sparsely wooded straths and a narrow coastal strip of marginal sheep grazing with a small amount of arable. The hills, flow bogs and moorlands are now almost devoid of any waders and passerines such as Meadow Pipit and Skylark are few and far between, the wooded straths (mainly of Birch and Rowan), once full of bird song are now virtually silent and the Sparrowhawks are long gone through lack of food. The coastal strip still has a few Lapwings, the odd Redshank and a few other odds and ends, but once again it's not a patch on what it once was when there were tumbling Lapwings, piping Redshank, warbling Curlews everywhere and even Corncrakes scraping away all through the night. The Buzzards still manage to find a living from the Rabbits and road kills and I suppose they will take any young birds they can find at fledging time, just as the remaining Corvids do.

So, in my neck of the woods predation by Corvids or Raptors is not the cause of the serious decline of all the waders and passerines, yes they do take prey who can deny it, that's what predators do and it will have some impact. The rapid decline began with the sudden intensive land changes that started with us in the late seventies and early eighties, huge areas of flow bogs and moorland were forested with Lodgepole Pine and Sitka Spruce. Most of this forestry is useless and not commercially recoverable, much of it having been blown over with the strong winds, the RSPB are buying up large areas, clearing it and attempting to return the land to the way it was before it was planted, some hope of that, it took 10,000 years since the last ice age to create the unique eco system of the flows and moors and we destroyed it in just a few years, however they're getting rid of the useless forestry and that's worth something. Large swathes of upland pasture and wet meadows were drained just for the government grants and subsidies that were easily available at that time, the majority of the drained land was never put to any agricultural use and still lies empty of nearly all the waders that used to feed and breed there, now most of the sheep that used to cover the hills, moors and upland pastures have gone also. Subsidies aint what they used to be I suppose. I haven't a clue how we can ever return this land to what is was or even if it's possible, nor I doubt will the money ever be available for trying and this is only one relatively small area of the UK.

nirofo.

Prey switching makes it quite possible for a predator to wipe out populations of prey without forcing themselves into starvation. Also this statement.

If they are to breed successfully then even higher densities of prey are a necessity

Click to expand...

.
does not make sense. Birds have many mechanisms for ensuring they can provision themselves and their young as successfully as possible. Larger territory, prey switching, reduced clutch sizes etc. They have no control over the density of prey so they are more likely to adapt themselves first. Again we are talking about corvids here and they have generally proven themselves to be highly adaptable historically.

Click to expand...

If Raptors are to breed successfully, by that I mean raise a reasonable sized brood, then they need enough prey items to ensure the young are fed sufficiently well for them to reach flying stage. Prey switching is not a problem for most Raptors and they will readily take any species or carrion that presents them with a reasonably easy opportunity, especially when they have young to feed. However, that assumes that there is enough prey in the territory to supply both adults and their young for what could be periods of up to 4 months or more. Raptors are not prone to wandering very far out of their own territory at nesting time, with the exception of the large Raptors, such as Eagles who will wander over large distances in search of food.

As you say, Corvids are more adaptable and will eat most things so are not as dependant on prey as Raptors, they are also more likely to travel outside their own nesting territory in search of food and are generally more successfull in raising young than Raptors.

nirofo.